What exactly are "cleaning marks" on lens

[Tony Egan]

I see the expression "light cleaning marks" quite often when shopping for used lens'. What exactly are they? Is this phrase used for multiple kinds of minor flaws? What effect do they have on lens quality? When does "light" become "heavy" and a real problem? Thanks.

 

[Ole]

"Cleaning marks" are small scratches, often concentric, on the outer glass surfaces of a lens. Some sellers use "light cleaning marks" and mean tiny scratches so small you need a loupe to see them, others mean that the lens has been cleaned with coarse sandpaper, but there's still some glass left.

It's surprising how much of the lens surface can be covered with cleaning marks without any influence on the performance. But anything described as "heavy cleaning marks" is probably best avoided.

 

[naturephoto1]

Tony,

I believe that cleaning marks can also refer to removal of some of the coatings off the lens that can be seen. This may be more visible on multicoated than single coated optics.

Rich

 

[Roger Hicks]

Tony,

I believe that cleaning marks can also refer to removal of some of the coatings off the lens that can be seen. This may be more visible on multicoated than single coated optics.

Rich

Except that top coats on multicoatings are often tougher and therefore less prone to scratching than some older MgF coatings. And, of course, the older lenses have had longer to get scratched.

All 'cleaning marks' reduce contrast. How far you find this acceptable depends on the lens, the extent of the marks, the intended use of the lens and the price. I avoid them more and more.

Cheers,

Roger (www.rogerandfrances.com)

 

[Campbell]

"Cleaning marks" doesn't really have a fixed meaning. It's a catch-all term used to indicate there are scratches or some similar kind of damage to the lens. It just sounds better to say "cleaning marks" instead of "gouges" or "scratches" or something like that.

 

[mikebarger]

And sometimes sellers get has no cleaning marks mixed up with has minor cleaning marks.

Although I agree with the above, light marks really don't impact the performance of the lens. I'm sure I have more of a negative impact than a few cleaning marks.

Mike